Decontamination method using heat and relative humidity for radish seeds achieves a 7-log reduction of Escherichia coli O157: H7 without affecting product quality

Y. B. Kim, H. W. Kim, M. K. Song, Min-Suk Rhee

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5 Citations (Scopus)


We developed a novel decontamination method to inactivate Escherichia coli O157:H7 on radish seeds without adversely affecting seed germination or product quality. The use of heat (55, 60, and 65 °C) combined with relative humidity (RH; 25, 45, 65, 85, and 100%) for 24. h was evaluated for effective microbial reduction and preservation of seed germination rates. A significant two-way interaction of heat and RH was observed for both microbial reduction and germination rate (P < 0.0001). Increases in heat and RH were associated with corresponding reductions in E. coli O157:H7 and in germination rate (P < 0.05). The order of lethality for the different treatments was generally as follows: no treatment < 55 °C/25-65% RH = 60 °C/25-45% RH = 65 °C/25% RH < 55 °C/85% RH = 60 °C/65% RH < 55 °C/100% RH = 60 °C/85-100% RH = 65 °C/45-100% RH. The most effective condition, 65 °C/45% RH, completely inactivated E. coli O157:H7 on the seeds (7.0. log. CFU/g reduction) and had no significant effect on the germination rate (85.4%; P > 0.05) or product quality. The method uses only heat and relative humidity without chemicals, and is thus applicable as a general decontamination procedure in spout producing plants where the use of growth chambers is the norm.

Original languageEnglish
Pages (from-to)42-46
Number of pages5
JournalInternational Journal of Food Microbiology
Publication statusPublished - 2015 May 8



  • Escherichia coli O157:H7
  • Heat
  • Radish seeds
  • Relative humidity (RH)
  • Seed decontamination

ASJC Scopus subject areas

  • Food Science
  • Microbiology
  • Safety, Risk, Reliability and Quality

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